Mobile external coupling with internal sealing cuff for branch vessel connection

ABSTRACT

An endovascular prosthesis includes a tubular body and a mobile external coupling. The tubular body includes a graft material and stents coupled thereto, a forms a lumen therethrough. The mobile external coupling extends outwardly from the tubular body. The mobile external coupling includes a graft material and is generally frustoconically shaped. The mobile external coupling includes a base coupled to the tubular body, a top spaced from the tubular body, and a coupling lumen disposed between the base and the top, wherein the coupling lumen is in flow communication with the body lumen. A cylindrical sealing cuff of graft material is attached to and extends from the top of the mobile external coupling towards the tubular body within the coupling lumen. The sealing cuff is configured to contact a portion of a branch vessel prosthesis and thereby provides an elongated interference seal between the branch vessel prosthesis and the mobile external coupling.

FIELD OF THE INVENTION

This invention relates generally to endoluminal medical devices andprocedures, and more particularly to an endoluminal prosthesis or grafthaving a mobile external coupling for connecting a main graft to abranch vessel graft.

BACKGROUND

Aneurysms and/or dissections may occur in blood vessels, and mosttypically occur in the aorta and peripheral arteries. Depending on theregion of the aorta involved, the aneurysm may extend into areas havingvessel bifurcations or segments of the aorta from which smaller “branch”arteries extend. Various types of aortic aneurysms may be classified onthe basis of the region of aneurysmal involvement. For example, thoracicaortic aneurysms include aneurysms present in the ascending thoracicaorta, the aortic arch, and branch arteries that emanate therefrom, suchas subclavian arteries, and also include aneurysms present in thedescending thoracic aorta and branch arteries that emanate therefrom,such as thoracic intercostal arteries and/or the suprarenal abdominalaorta and branch arteries that emanate therefrom, which could includerenal, superior mesenteric, celiac and/or intercostal arteries. Lastly,abdominal aortic aneurysms include aneurysms present in the aorta belowthe diaphragm, e.g., pararenal aorta and the branch arteries thatemanate therefrom, such as the renal arteries.

The thoracic aorta has numerous arterial branches. The arch of the aortahas three major branches extending therefrom, all of which usually arisefrom the convex upper surface of the arch and ascend through thesuperior thoracic aperture. The brachiocephalic artery originatesanterior to the trachea. The brachiocephalic artery divides into twobranches, the right subclavian artery (which supplies blood to the rightarm) and the right common carotid artery (which supplies blood to theright side of the head and neck). The left common carotid artery arisesfrom the arch of the aorta just to the left of the origin of thebrachiocephalic artery. The left common carotid artery supplies blood tothe left side of the head and neck. The third branch arising from theaortic arch, the left subclavian artery, originates behind and just tothe left of the origin of the left common carotid artery and suppliesblood to the left arm.

For patients with thoracic aneurysms of the aortic arch, surgery toreplace the aorta may be performed where the aorta is replaced with afabric substitute in an operation that uses a heart-lung machine. Insuch a case, the aneurysmal portion of the aorta is removed or openedand a substitute lumen is sewn across the aneurysmal portion to span it.Such surgery is highly invasive, requires an extended recovery periodand, therefore, cannot be performed on individuals in fragile health orwith other contraindicative factors.

Alternatively, the aneurysmal region of the aorta can be bypassed by useof am endoluminally delivered tubular exclusion device, e.g., by astent-graft placed inside the vessel spanning the aneurysmal portion ofthe vessel, to seal off the aneurysmal portion from further exposure toblood flowing through the aorta. A stent-graft can be implanted withouta chest incision, using specialized catheters that are introducedthrough arteries, usually through incisions in the groin region of thepatient. The use of stent-grafts to internally bypass, within the aortaor flow lumen, the aneurysmal site, is also not without challenges. Inparticular, where a stent-graft is used at a thoracic location, caremust be taken so that critical branch arteries are not covered oroccluded by the stent-graft yet the stent-graft must seal against theaorta wall and provide a flow conduit for blood to flow past theaneurysmal site. Where the aneurysm is located immediately adjacent tothe branch arteries, there is a need to deploy the stent-graft in alocation which partially or fully extends across the location of theorigin of the branch arteries from the aorta to ensure sealing of thestent-graft to the artery wall.

To accommodate side branches, main vessel stent-grafts having afenestration or opening in a side wall thereof may be utilized. The mainvessel stent graft is positioned to align its fenestration with theostium of the branch vessel. In use, a proximal end of the stent-graft,having one or more side openings, is prepositioned and securely anchoredin place so that its fenestrations or openings are oriented whendeployed to avoid blocking or restricting blood flow into the sidebranches. Fenestrations by themselves do not form a tight seal orinclude discrete conduit(s) through which blood can be channeled intothe adjacent side branch artery. As a result, blood leakage is prone tooccur into the space between the outer surface of the main aortic stentgraft and the surrounding aortic wall between the edge of the graftmaterial surrounding the fenestrations and the adjacent vessel wall.Similar blood leakage can result from post-implantation migration ormovement of the stent-graft causing misalignment between thefenestration(s) and the branch artery(ies), which may also result inimpaired flow into the branch artery(ies).

In some cases, the main vessel stent graft is supplemented by anotherstent-graft, often referred to as a branch stent-graft. The branch graftis deployed through the fenestration into the branch vessel to provide aconduit for blood flow into the branch vessel. The branch stent-graft ispreferably sealingly connected to the main graft in situ to preventundesired leakage between it and the main stent-graft. This connectionbetween the branch graft and main graft may be difficult to createeffectively in situ and is a site for potential leakage.

In some instances, branch graft extensions (stent-grafts) areincorporated into the main stent-graft. Such branch graft extensions arefolded or collapsed against the main stent-graft for delivery andrequire complicated procedures, requiring multiple sleeves and guidewires, to direct the branch extension into the branch vessel andsubsequently expand. Further, in some instances, such branchstent-grafts tend to return to their folded or collapsed configuration,and thus do not provide an unobstructed flow path to the branch vessel.

Thus, there remains a need in the art for improvements in stent graftstructures for directing flow from a main vessel, such as the aorta,into branch vessels emanating therefrom, such as branch vessels of theaortic arch.

SUMMARY OF THE INVENTION

Embodiments hereof relate to an endovascular prosthesis includes atubular body and a mobile external coupling. The tubular body includes agraft material and stents coupled thereto, and forms a lumentherethrough. The mobile external coupling extends outwardly from thetubular body. The mobile external coupling includes graft material andis generally frustoconically shaped. The mobile external couplingincludes a base coupled to the tubular body, a top spaced from thetubular body in its extended configuration, and a coupling lumendisposed between the base and the top, wherein the coupling lumen is inflow communication with the body lumen. A cylindrical sealing cuffformed from a graft material is attached to and extends from the top ofthe mobile external coupling towards the tubular body. The sealing cuffis configured to contact a portion of the branch vessel prosthesis andthereby provides an elongated interference seal between the branchvessel prosthesis and the mobile external coupling.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic side view of an endoluminal stent-graftillustrating an embodiment hereof.

FIG. 2 is a schematic close up illustration of a portion of thestent-graft of FIG. 1.

FIG. 3 is a schematic illustration of the mobile external coupling ofthe stent-graft of FIG. 1.

FIG. 4 is a schematic illustration of a stent ring disposed at the topof the mobile external coupling of the stent-graft of FIG. 1.

FIG. 5A is a schematic illustration of the mobile external coupling ofthe stent-graft having a coupling deployment mechanism coupled thereto.

FIG. 5B is a schematic illustration of the mobile external coupling ofthe stent-graft having a coupling deployment mechanism coupled thereto.

FIG. 6 is a schematic illustration of the mobile external couplinghaving a portion cut-away to illustrate an internal sealing cuff.

FIG. 7 is a schematic illustration of the internal sealing cuff of FIG.6 removed from the mobile external coupling.

FIG. 8 is a schematic illustration of the mobile external couplinghaving a portion cut-away to illustrate the internal sealing cuff havinga branch vessel conduit deployed therein.

FIG. 9 is an illustration of a mobile external coupling with an internalsealing cuff, wherein the internal sealing cuff includes acircumferential stent.

FIGS. 10-12 are different views of the mobile external coupling of FIG.9 with an internal sealing cuff having a circumferential stent.

FIGS. 13-14 are views of the mobile external coupling of FIG. 9 with aninternal sealing cuff having a circumferential stent and showing abranch vessel conduit deployed in the in the mobile external coupling.

FIG. 15 is an illustration of an embodiment of a mobile externalcoupling with an external sealing cuff.

FIG. 16 is a schematic illustration of a stent-graft delivery device.

FIG. 17 is a schematic illustration of a proximal portion of thestent-graft delivery device of FIG. 16.

FIG. 18 is a schematic illustration of a distal portion of thestent-graft delivery device of FIG. 16 with a stent-graft disposedtherein.

FIG. 19 is a schematic illustration of a stent graft with a side tubefor the second guide wire extending through a lumen of the tubular bodyof the stent-graft and through a lumen of the mobile external coupling.

FIG. 20 is a schematic illustration of a stent stop including groovesfor the side tube.

FIG. 21 is a schematic illustration of a stent capture assembly of thedelivery system of FIG. 16.

FIG. 22 is a schematic illustration of the tip of the delivery system ofFIG. 16.

FIGS. 23-26 are schematic illustrations of progressive steps ofdeploying the stent-graft from the delivery system of FIG. 16.

FIGS. 27-32 are schematic illustrations of progressive steps a methodfor delivering and deploying the stent-graft of FIG. 1 and a branchstent-graft to a target location

DETAILED DESCRIPTION

Specific embodiments are now described with reference to the figures,wherein like reference numbers indicate identical or functionallysimilar elements. Unless otherwise indicated, for the delivery systemthe terms “distal” and “proximal” are used in the following descriptionwith respect to a position or direction relative to the treatingclinician. “Distal” and “distally” are positions distant from or in adirection away from the clinician, and “proximal” and “proximally” arepositions near or in a direction toward the clinician. For the stentgraft device “proximal” is the portion nearer the heart by way of bloodflow path while “distal” is the portion of the stent graft further fromthe heart by way of blood flow path.

With reference to FIGS. 1-4, a stent-graft 100 is configured forplacement in a vessel such as the aorta. Stent-graft 100 includes graftmaterial 102 coupled to circumferential stents 104. Graft material 102may be coupled to circumferential stents 104 using stitching 110 orother means known to those of skill in the art. In the embodiment shownin FIGS. 1-2 circumferential stents 104 are coupled to an outsidesurface of graft material 102. However, circumferential stents 104 mayalternatively be coupled to an inside surface of graft material 102.Graft material 102 may be any suitable graft material, for example andnot limited to, woven polyester, DACRON® material, expandedpolytetrafluoroethylene, polyurethane, silicone, or other suitablematerials. Circumferential stents 104 may be any conventional stentmaterial or configuration. As shown, circumferential stents 104 arepreferably made from a shape memory material, such as thermally treatedstainless steel or nickel-titanium alloy (nitinol), and are formed intoa zig-zag configuration. Stent-graft 100 includes a proximal end 106, adistal end 108, and a body 107 therebetween. Proximal stent 112 anddistal stent 114 may extend outside of the graft material 102, as shown,and may also be generally described as anchor stents or crown stents inthe art. Body 107 has a lumen 116 therethrough. Stent-graft 100 furtherincludes a mobile external coupling 120, described in detail below.Except for the mobile external coupling 120, stent-graft 100 may besimilar to the Medtronic, Inc.'s VALIANT® thoracic stent-graft, or otherknown stent-grafts.

Mobile external coupling 120 is disposed on an outside surface ofstent-graft 100 corresponding to an opening in graft material 102.Mobile external coupling 120 is generally frustoconically shaped. Mobileexternal coupling 120 includes graft material 128 having a base 124 anda top 126. Graft material 128 is preferably the same type of graftmaterial as graft material 102 of the body 107 and is preferably acontinuation of graft material 102, although graft material 128 can be aseparate piece of graft material attached to graft material 102. Asshown in FIGS. 3 and 4, a wire shaped as a circle or ring 122 may bedisposed at top 126 and may be coupled to graft material 128 by creatinga blanket stitch which captures the edge of the graft material 128 andthe ring 122 with suture material. The suture describes a helical pathas it progresses around the ring 122. The density of the stitch is suchthat it essentially covers the ring with suture. Although mobileexternal coupling 120 is described as generally frustoconical in shape,base 124 is preferably generally elliptical rather than circular. Base124 may have, for example and not by way of limitation, a long axis ofapproximately 20-30 mm and a short axis of approximately 15-20 mm.Further, the height of mobile external coupling 120 may be approximately10-15 mm. Further, the diameter of the top 126 of mobile externalcoupling may be approximately 6-9 mm if it is to be used at the junctionof the aorta and left common carotid artery or the junction of the aortaand left subclavian artery. If the mobile external coupling 120 is to beused at the junction of the aorta and the brachiocephalic artery, thediameter of the top 126 may be approximately 8-12 mm.

Referring to FIGS. 5A-5B, a coupling deployment device 132 may becoupled to mobile external coupling 120 for elevating top 126 of mobileexternal coupling 120 into the ostium of the target branch vessel duringdeployment and ensuring that mobile external coupling 120 fully evertsinto the ostium. In an embodiment, coupling deployment device 132 may bea shape memory helical stent coupled to graft material 128 as shown inFIG. 5A. The helical stent is configured to create the frustoconicallyshaped outline such that bottom 124 has a larger diameter than top 124,as described in U.S. patent application Ser. No. 12/425,628, filed Apr.17, 2009, herein incorporated by reference in its entirety. In anotherembodiment, coupling deployment device 132 may be a shape set wirecoupled to a circumferential stent 104 of stent grail 100 via a crimp142 as shown in FIG. 5B. The shape set wire has one or more spring armportions that extend generally longitudinally along mobile externalcoupling 120 such that mobile external coupling 120 self-extend awayfrom body 107 when mobile external coupling 120 is released from itsdelivery system, as described in U.S. patent application Ser. No.12/770,566, filed, Apr. 29, 2010, herein incorporated by reference inits entirety. In yet another embodiment, in order to deploy mobileexternal coupling 120 into the ostium of the target branch vessel, graftmaterial 128 may be a woven fabric with warp yarn which run generallyparallel to a longitudinal axis of the mobile external couplingincluding a shape memory material as described in U.S. patentapplication Ser. No. 12/425,616, filed Apr. 17, 2009, hereinincorporated by reference in its entirety.

Mobile external coupling 120 allows for significant flexibility inaligning stent-graft 100 with a branch vessel because the top of themobile external coupling 120 when deployed can move longitudinallyrelative to the longitudinal axis of the body 107. This mobility is dueto the shape of mobile external coupling 120 and can be further improvedby utilizing some excess graft material 128 when forming mobile externalcoupling 120. Thus, if stent-graft 100 is not perfectly aligned with abranch vessel, the top 126 of mobile external coupling 120 can move orshift to cause top to extend into the branch vessel. Further, due to theenergy stored in coupling deployment device 132 while in the delivery orcollapsed configuration in its delivery system, mobile external coupling120 pops out from body 107 of stent-graft 100 when released from asleeve of the delivery system during delivery and deployment at thetarget site. Thus, when mobile external coupling 120 is released fromits delivery configuration, as explained in more detail below, mobileexternal coupling 120 will self expand to extend away from body 107.This prevents bunching, kinking or collapse of the mobile externalcoupling 120 when released from the delivery system.

As will be explained in more detail herein, a branch vessel prosthesisor conduit is delivered and deployed through mobile external coupling120. After implantation, pulsatile expansion and/or other movement ofthe branch vessel may occur during the cardiac cycle. If the branchvessel prosthesis is balloon-expandable, such movement of the branchvessel may eventually degrade the seal between mobile external coupling120 and a branch vessel prosthesis 143 due to plastic deformation of thematerial of branch vessel prosthesis 143. Referring now to FIGS. 6-8, aninternal sealing cuff 134 is attached to the top 126 of mobile externalcoupling 120 for producing an elongated interference seal orlongitudinal contact zone 146 (shown in FIG. 8) between branch vesselprosthesis 143 (shown in FIG. 8) and mobile external coupling 120. FIG.6 is a schematic illustration of mobile external coupling 120 having aportion cut-away to reveal internal sealing cuff 134 extending therein,and FIG. 7 is a schematic illustration of internal sealing cuff 134removed from mobile external coupling 120. FIG. 8 is a schematicillustration of mobile external coupling 120 including internal sealingcuff 134 with a branch vessel prosthesis 143 deployed therein.Regardless whether branch vessel prosthesis 143 is balloon-expandable orself-expanding, internal sealing cuff 134 enhances sealing betweenbranch vessel prosthesis 143 and mobile external coupling 120 due to theincreased amount of contact zone 146.

Internal sealing cuff 134 is generally cylindrically shaped and extendsproximally or inwardly from the top 126 of mobile external coupling 120in a direction towards body 107 indicated by directional arrow 135, suchthat sealing cuff 134 is internal to mobile external coupling 120.Internal sealing cuff 134 and mobile external coupling 120 share thesame longitudinal axis 144, and internal sealing cuff 134 includes alumen 137 extending therethrough which is in fluid communication withcoupling lumen 130 of mobile external coupling 120. Internal sealingcuff 134 may be formed of a graft material 136 having a base 138 and atop 140. Graft material 136 may be any suitable graft material, forexample and not limited to, woven polyester, DACRON® material, expandedpolytetrafluoroethylene (PET), polyurethane, silicone, or other suitablematerials. In one embodiment, graft material 136 is a pliable clothmaterial suitable that can withstand the expansion or inflation force ofthe branch vessel prosthesis without crumpling or failing. If branchvessel prosthesis 143 is balloon-expandable, a pliable cloth graftmaterial is unlikely to create plastic deformation of branch vesselprosthesis 143. In an example, and not by way of limitation, graftmaterial 136 may be a seamless woven tube of PET cloth. Top 140 ofinternal sealing cuff 134 is attached to top 126 of mobile externalcoupling 120 using any suitable mechanical method such as sewing oradhesive. For example, the top edge of graft material 128 of mobileexternal coupling 120 and the top edge of graft material 136 of internalsealing cuff may be approximated and held together by a blanket stitch.If mobile external coupling 120 includes ring 122 (see FIGS. 3-4)disposed at the top thereof, internal sealing cuff 134 may be attachedto the mobile external coupling 120 by placing the edge of the graftmaterial 136 of internal sealing cuff 134 adjacent the edge of graftmaterial 128 of mobile external coupling and by creating a blanketstitch which captures the edges of the graft material 128, graftmaterial 136, and the ring 122 with suture material. The suturedescribes a helical path as it progresses around the ring 122. Thedensity of the stitch is such that it essentially covers the ring withsuture material.

The length of internal sealing cuff 134 creates the length or amount oflongitudinal contact zone 146 between branch vessel prosthesis 143 andmobile external coupling 120. In one example, internal sealing cuff 134may be approximately 1 cm in length. When branch vessel prosthesis 143is deployed within mobile external coupling 120, interference seal 146may extend all or part of the length of internal sealing cuff 134. Thediameter of internal sealing cuff 134 is preferably smaller than thedeployed diameter of branch vessel prosthesis 143. In one embodiment,the diameter of internal sealing cuff 134 may be up to approximately 30%smaller than the deployed diameter of branch vessel prosthesis 143. Forexample, if mobile external coupling 120 is to be used at the junctionof the aorta and left common carotid artery or the junction of the aortaand left subclavian artery in which a prosthesis used in the branchvessel has a deployed diameter between 6-9 mm, the diameter of internalsealing cuff 134 may be approximately 4-6 mm. If the mobile externalcoupling 120 is to be used at the junction of the aorta and thebrachiocephalic artery in which a prosthesis used in the branch vesselhas a deployed diameter between 8-12 mm, the diameter of internalsealing cuff 134 may be approximately 5.5-8.5 mm.

In an embodiment depicted in FIGS. 9-14, internal sealing cuff 134 maybe reinforced or supported with a circumferential stent 148 coupledthereto. Stent 148 imparts longitudinal integrity to internal sealingcuff 134 to properly orient the cuff within mobile external coupling 120and further prevent collapse of the cuff into a narrow band and/orprevent the cuff from balling or rolling up. Graft material 136 ofinternal sealing cuff 134 may be coupled to circumferential stent 148using stitching or other means known to those of skill in the art, andmay stent 148 be coupled to an outside or inside surface of graftmaterial 136. Circumferential stent 148 may be any conventional stentmaterial or configuration. As shown, circumferential stent 148 may madefrom a shape memory material, such as thermally treated stainless steelor nickel-titanium alloy (nitinol), and are formed into a zig-zag orsinusoidal configuration. In another embodiment, circumferential stent148 may be formed from a plastically deformable material. FIG. 9 showsmobile external coupling 120 pulled distally to better see internalsealing cuff 134 with stent 148. FIGS. 13 and 14 show branch vesselprosthesis 143 deployed within internal sealing cuff 134, with FIG. 13showing mobile external coupling 120 pulled distally to better seeinternal sealing cuff 134.

In an embodiment, circumferential stent 148 may be undersized withrespect to internal sealing cuff 134 to provide a more effective sealbetween the cuff and branch vessel prosthesis 143. For example, if thediameter of internal sealing cuff 134 is approximately 8 mm, undersizedcircumferential stent 148 may have a shape memory diameter ofapproximately 6 mm, or 20% less than the diameter of internal sealingcuff 134. Deployment of branch vessel prosthesis 143 into internalsealing cuff 134 results in expansion of prosthesis 143 to the limitingdiameter of internal sealing cuff 134. Thus, even if movement of branchvessel prosthesis 143 occurs after implantation, the shape memory ofundersized circumferential stent 148 urges internal sealing cuff 134 tothe shape memory diameter of undersized circumferential stent 148 tothereby compensate for the movement and retain the seal between internalsealing cuff 134 and branch vessel prosthesis 143. Undersizedcircumferential stent 148 and branch vessel prosthesis 143 are twoelastic pieces exerting opposing forces onto each other. In other words,because branch prosthesis wants to expand to a larger diameter than thelimiting diameter of stent 148, branch prosthesis 143 provides anoutward force and stent 148 provides a counteracting inward force thatthat the seal is maintained between internal sealing cuff 134 and branchprosthesis 143. When a balloon expandable stent (BES) is used as abranch vessel prosthesis, the elastic interference interaction describedmay also exist, but only to the extent that elastic rebound of the BESis minimal.

FIG. 15 illustrates another embodiment of a cuff for producing anelongated interference seal between the branch vessel prosthesis and themobile external coupling. Particularly, an external sealing cuff 1534 isattached to the top 126 of mobile external coupling 120 for producing aseal or longitudinal contact zone between a branch vessel prosthesis(not shown in FIG. 15) and mobile external coupling 120. Similar tointernal sealing cuff 134 described above, external sealing cuff 1534 isgenerally cylindrically shaped and includes graft material 1536 having abase 1538 and a top 1540. External sealing cuff 1534 operates in asimilar manner as internal sealing cuff 134 to enhance sealing between abranch vessel prosthesis and mobile external coupling 120 due to theincreased amount of the seal or contact zone. However, base 1538 ofexternal sealing cuff 1534 is attached to the top 126 of mobile externalcoupling 120 and external sealing cuff 1534 extends distally oroutwardly from the top 126 of mobile external coupling 120 in adirection away from the body of the main-stent graft (not shown in FIG.15) indicated by directional arrow 1550, such that sealing cuff 1534 isexternal to mobile external coupling 120. As shown on FIG. 15, thediameter of external sealing cuff 1534 is preferably smaller than thedeployed diameter of the branch vessel prosthesis, and in one embodimentmay be up to approximately 30% smaller than the deployed diameter of thebranch vessel prosthesis and top 126 of mobile external coupling 120.More particularly, the diameter of the top of frustoconically-shapedmobile external coupling 120 is approximately equal to the deployeddiameter of the branch vessel prosthesis. External sealing cuff 1534extends distally or outwardly from the top 126 of mobile externalcoupling 120, but has a diameter of up to approximately 30% smaller thantop 126 for creating the seal or longitudinal contact zone between thebranch vessel prosthesis and mobile external coupling 120.

FIGS. 16-26 show an example of a delivery system that can be used todeliver stent-graft 100 to the target location within a vessel. FIG. 16is a schematic partial cross-sectional view of a stent-graft deliverysystem 200 with stent-graft 100 disposed therein. Stent-graft deliverysystem 200 includes a distal portion 201 and a proximal portion 250.Distal portion 201 is preferably used to load and deliver stent-graftsection 100. Proximal portion 250 includes components such as thosefound conventionally in catheter delivery systems.

The components of the proximal portion 250 of the delivery system 100may preferably include those shown in FIGS. 16 and 17, althoughadditional and/or alternative components are also contemplated. Inparticular, proximal portion 250 of delivery system 200 includes a TouhyBorst adaptor 266, a stent capture slider 268, a side port extension262, a side lumen access 264, a rear grip 260, a screw gear 258, anexternal slider 254 including a button 256, a front grip 252, and astrain relief 269. One or more hemostatic valves may be provided infront grip 106, for example, as described in U.S. Published PatentApplication Publication No. 2006/0229561, commonly assigned with thepresent application, which is incorporated herein by reference in itsentirety. The delivery system 200 as described is generally similar tothe Xcelerant Delivery System, sold by Medtronic, Inc., but may be anyconventional therapy delivery system, with modifications noted in detailbelow. Delivery system 200 is generally a single use, disposable devicewith the stent-graft 100 mounted on within distal end 201 of thedelivery system 200.

FIG. 18 is a schematic view of the distal portion 201 of delivery system200. Distal portion 201 includes a tapered tip 202 that is flexible andable to provide trackability in tight and tortuous vessels. Other tipshapes such as bullet-shaped tips could also be used. The tip 202includes a lumen 204 disposed therethrough for accommodating a firstguide wire 220.

The tapered tip 202 includes a tapered outer surface 216 that graduallydecreases in diameter in a distal direction. More particularly, taperedouter surface 216 has a first diameter at a proximal end and graduallydecreases in diameter distally, i.e., in the direction away from theoperator. Tapered outer surface 216 further includes a groove 218, asbest seen in FIG. 22, for accommodating a second guide wire 222 within alumen of a side tube 224. A shoulder 212 reduces the diameter of aproximal portion of tip 202 to provide a sleeve landing surface 226.Shoulder 212 is generally annular and perpendicular to a longitudinalaxis of stent-graft delivery system 200.

An outer sleeve 210 of stent-graft delivery system 200 extends over theouter cylindrical surface of sleeve landing surface 226 and abutsagainst shoulder 212 when the stent-graft delivery system 200 is in apre-deployment configuration, as shown in FIG. 18. Stent-graft deliverysystem 200 further includes a stent capture system 290 that captures andholds an end of stent-graft 100, as explained in more detail below.

Stent-graft delivery system 200 also includes an inner tube 205 that iscoupled to a tip lumen 204 such that first guide wire 220 may extend thelength of delivery system 200. A stent capture tube 284 of stent capturesystem 290 surrounds inner tube 205, as explained in more detail below.A stop 208 is located at a distal end of stent-graft 100 whenstent-graft 100 is loaded onto the delivery system 200. Stop 208prevents longitudinal movement of stent-graft 100 as outer sleeve 210 isretracted or otherwise removed to release stent-graft 100. Stop 208includes a lumen 209 through which stent capture tube 284 and inner tube205 are disposed. Stop 208 further includes grooves 214 disposed betweenlandings 215. Stop 208 in this embodiment extends proximally along thelength of the delivery system 200. Side tube 224 may be disposed in anyof the grooves 214 and extend proximally the length of the deliverysystem to be control at proximal portion 250 through side lumen access264. Stent-graft 100 is disposed within outer sleeve 210 in a compressedor delivery configuration wherein the diameter of stent-graft 100 isreduced such that it can be inserted through the vasculature.

Second guide wire 222 extends through stent-graft delivery system 200through a lumen of side tube 224, which extends through lumen 116 ofstent-graft 100, through lumen 130 of mobile external coupling 120,between outer sleeve 210 and body 107, and out a distal end of outersleeve 210 through groove 218 of tip 202. In the delivery or compressedconfiguration, mobile external coupling 120 may be folded as shownschematically in FIGS. 18 and 19.

Stent capture system 290 is shown in FIG. 22. Stent capture system 290includes a spindle 270 and a stent capture assembly 280. Stent capturesystem 290 may be similar to or identical to stent capture systemdescribed in U.S. Published Application Publication No. 2009/0276027,published Nov. 5, 2009, which is incorporated by reference herein in itsentirety.

Spindle 270 shown in FIG. 21 is fixed to inner shaft 205 adjacent aproximal end of tip 202. Spindle 270 includes a lumen (not shown)through which inner shaft is disposed. Spindle 270 may also be slidablerelative to inner shaft 205, for example, as described in U.S. PublishedApplication Publication No. 2009/0276027. Spindle 270 includes a numberof spindle pins 274 disposed around the circumference of the spindlebody. A spindle groove 272 is formed between each pair of adjacentspindle pins 274. A single stent crown (not shown) of proximal anchorstent 112 wraps around each spindle pin 274 and is held in place by astent capture fitting arm 286 of the stent capture assembly 280 duringstent-graft delivery. When the stent capture assembly 280 is retracted,the stent crowns are freed from the spindle pins 274 and proximal anchorstent 112 expands into position in the vessel. The spindle 270 can bemade of any rigid and/or compliant biocompatible material and can beformed as a single unit and/or assembled from individual parts. Thoseskilled in the art will appreciate that the spindle 270 can made of anybiocompatible material and can be formed as a single unit and/orassembled from individual parts. Other embodiments of spindle 270, asdescribed for example in U.S. Published Application Publication No.2009/0276027, may also be used.

Stent capture assembly 280 includes a stent capture fitting 282 and astent capture shaft 284. The stent capture assembly 280 defines a stentcapture assembly lumen (not shown) along its length through which innershaft 205 can slide. The diameter of the stent capture assembly lumen islarge enough that the inner shaft can slide within the stent captureassembly lumen. The stent capture shaft 284 advances the stent capturefitting 282 to hold the stent crowns wrapped around spindle pins 274 inplace during delivery and initial deployment of stent-graft 100. Stentcapture shaft 284 retracts the stent capture fitting 282 to release theproximal anchor stent 112 of the stent-graft 100 from the deliverydiameter. The stent capture shaft 284 is long enough the reach throughthe vasculature from the stent graft deployment site in the vessel tothe clinician. The proximal end of the stent capture shaft 284 isattached to stent capture slider 268 shown in FIGS. 16 and 17 formanipulation by the clinician during stent-graft delivery. Those skilledin the art will appreciate that the stent capture assembly 280 can madeof any biocompatible material and can be formed as a single unit and/orassembled from individual parts. The stent capture shaft 284 may beconstructed of a rigid plastic, such as PEEK polyetheretherketone,polyimide, nylon, or the like. The stent capture shaft 284 canalternatively be constructed of a flexible metal tube such as nitinol,stainless steel, or the like.

The stent capture fitting 282 in cooperation with the spindle 270,retains one end of the stent-graft during stent-graft delivery. In theillustrated embodiment, the stent capture fitting 282 includes a stentcapture body 285 having a number of stent capture fitting arms 286disposed around the circumference of the stent capture body 285. Thestent capture body 285 defines a number of stent capture grooves 288between each of the stent capture fitting arms 286 to receive the barestent crowns. The stent capture fitting arms 286 can be substantiallyparallel to the central axis of the stent capture fitting 282, i.e., theaxis along the stent capture shaft 284. In other embodiments, the stentcapture fitting arms 286 can curve toward or away from the axis of thestent capture fitting 282 as desired for a particular purpose. When thestent capture fitting 282 is retracted, the stent capture fitting arms286 release the bare stent crowns, and the proximal anchor stent 112expands into position in the vessel. The stent capture fitting 282 canbe made of any rigid and/or compliant biocompatible material and can beformed as a single unit and/or assembled from individual parts. Thestent capture fitting may be fabricated from a variety of materials.This may include rigid plastic materials such as PEEKpolyetheretherketone, polycarbonate, or the like, and may also includemetals such as stainless steel. In one embodiment, a hard plastic orhighly polished metal is desirable for the stent capture fitting 282 toavoid damage to the stent surface which is in contact with the stentcapture fitting 282. The stent capture fitting 282 can be fastened tothe stent capture shaft 284 by bonding the two with adhesive orthreading the two components together. The stent capture fitting 282 mayalternatively be insert molded directly on the stent capture shaft 284.

Outer sleeve 210 is a hollow tube and defines a lumen therein withinwhich stent-graft 100, stent capture system 290, side shaft 224 andinner tube 205 are disposed in the delivery configuration shown in FIG.18. In a first step for deploying the stent-graft, outer sleeve 210 ismoved proximally, retracted, relative to inner tube 205 to a positionadjacent the mobile external coupling 120, as shown in FIG. 23. Outersleeve 210 may be refracted by retracting external slider 254 bycounter-clockwise rotational movement, as shown in FIG. 23A. Thisrotational movement provides a slower retraction of outer sleeve 210 acontrolled release of the proximal portion of stent-graft 100, as shownin FIG. 23. Due to stent capture assembly 290 holding proximal anchorstent 112 of the stent-graft 100 in the radially compressed deliveryconfiguration, and the relatively short distance to the mobile externalcoupling 120, the portion 190 of the stent that is free to expand isrelatively short, as shown in FIG. 23. However, as also shown in FIG.23, mobile external coupling 120 is no longer constrained by outersleeve 210, and the energy stored in coupling deployment device 132 isreleased such that mobile external coupling 120 pops-out from body 107and into the ostium of the branch vessel.

The side tube 224 may be removed by withdrawing it proximally from sidelumen access 264 at the proximal portion 250 of the delivery system 200.Second guide wire 222 may be manipulated to adjust the location ororientation of mobile external coupling 120. Optionally, side tube 224may remain in place while mobile external coupling 120 is adjusted.

After mobile external coupling 120 is properly located in the ostium ofthe branch vessel, outer sleeve 210 may be further retracted, as shownin FIG. 24, by further retracting external slider 254. FIG. 24 showsouter sleeve 210 further retracted, but not fully retracted, as distalanchor stent 114 of stent-graft 100 remains disposed within outer sleeve210. When outer sleeve 210 is fully retracted, as shown in FIG. 25, theentire stent-graft body, except for the portion retained by stentcapture assembly 290, is in the radially expanded or deployedconfiguration. This further retraction of external slider 254 may bedone more quickly than the initial controlled retraction by pressingtrigger 256 and sliding external slider 254, as shown in FIG. 24A,rather than rotating external slider 254. However, those of ordinaryskill in the art will recognize that the initial retraction and furtherretraction of external slider 254 may each be accomplished throughrotation of external slider 254 or sliding of external slider 254.Further, other methods and devices for retracting outer sleeve 210 couldbe utilized, as known to those of ordinary skill in the art.

After outer sleeve 210 is fully retracted, stent capture slider 268 maybe retracted proximally such that stent capture assembly 280 movesproximally away from spindle 270. Stent capture fitting arms 288 therebyrelease proximal anchor stent 112 such that proximal anchor stentexpands, as shown in FIG. 26.

The stent-graft delivery system 200 described herein is only an exampleof a delivery system that can be used to delivery and deploy stent-graft100 and many other delivery systems known to those skilled in the artcould be utilized. For example, stent-graft 100 could be mounted onto aballoon to be expanded when at the target site. Otherstent-graft-delivery systems, for example and not by way of limitation,the delivery systems described in U.S. Published Patent ApplicationPublication Nos. 2008/0114442 and 2008/0262590 and U.S. Pat. No.7,264,632, and U.S. patent application Ser. Nos. 12/425,616 and12/425,628, each filed Apr. 17, 2009, each of which is incorporatedherein by reference in its entirety, may be utilized to deliver anddeploy stent-graft 100.

FIGS. 27-32 schematically show a method of delivering stent-graft 100 toa target site in a main vessel and a method of delivering a branchstent-graft to branch vessel. In the example described herein, thestent-graft 100 is delivered and deployed into the aorta 300. Portionsof the aorta 300 include the ascending aorta 302, the aortic arch 304,and the descending aorta 306. Branching from the aortic arch are thebrachiocephalic trunk 308, the left common carotid artery 314, and theleft subclavian artery 316. The brachiocephalic trunk branches into theright subclavian artery 310 and the right common carotid artery 312. Ananeurysm 318 in the area of the aortic arch 304 can be difficult tobypass or exclude with a stent-graft because blood flow to the brancharteries must be maintained.

In the embodiment shown in FIGS. 27-32, the aneurysm is sufficientlyclose to brachiocephalic trunk 308 that the stent-graft 100 must extendbetween the brachiocephalic trunk 308 and the heart. In such a case andwith a stent-graft 100 with only a single mobile external coupling 120,the mobile external coupling 120 is designed so as to be deployed intothe brachiocephalic trunk 308 to perfuse the brachiocephalic trunk 308.Prior to the procedure for inserting stent-graft 100, surgical by-passprocedures installing bypass grafts or vessels (not shown) are performedto connect the right common carotid artery 312 to the left commoncarotid artery 314 and the left common carotid artery to the leftsubclavian artery 316. Such surgical bypass procedures may be performedone to two weeks prior to insertion of the stent-graft, and presentsignificantly less complications and risk than a surgical solution torepair an aneurysm 318 in the aortic arch. In this manner, maintainingperfusion to the brachiocephalic trunk 308, and hence the right commoncarotid artery 312, maintains perfusion to the left common carotidartery 314 and the left subclavian artery 316 Thus, the openings (orostia) to these branch vessels directly from the aortic arch may beblocked by stent-graft 100. In the alternative, multiple mobile externalcouplings 120 may be provided in stent-graft 100. Further, if theaneurysm only affects the left common carotid artery 314 and the leftsubclavian artery 316, only one by-pass between the left common carotidartery 314 and the left subclavian artery needs to be performed, andthen a stent-graft with a single mobile external coupling 120 can beutilized to perfuse the left common carotid artery 314. Alternatively,in such a situation, a stent-graft with two mobile external couplingsmay be provided, one for each of the branch vessels noted. Accordingly,while the embodiment of stent-graft 100 in the method described belowincludes a single mobile external coupling 120 and the mobile externalcoupling is deployed in the brachiocephalic trunk 308, those skilled inthe art would recognize that multiple mobile external couplings can beused and the mobile external coupling(s) may be deployed in other brancharteries.

FIG. 27 shows the first guide wire 220 advanced through the descendingaorta 306, through the aortic arch 304, and into the ascending aorta 302and second guide wire 222 advanced through the descending aorta 306,through the aortic arch 304, and into brachiocephalic trunk 308. Guidewires 200, 222 are typically inserted into the femoral artery and routedup through the abdominal aorta, and into the thoracic aorta, as is knownin the art. Second guide wire 222 may also be locked at its distal endso as to prevent second guide wire 222 from retracting. Access from thebrachiocephalic artery or carotid artery may be used to lock secondguide wire 222 at its distal or superaortic end, as is known to those ofordinary skill in the art as a through-and-through wire technique.

FIG. 28 shows stent-graft delivery system 200, with stent-graft 100compressed therein, advanced over guide wires 220, 222 to the targetlocation in the aortic arch 304. The location of the stent-graftdelivery system 200 and/or the stent-graft 100 may be verifiedradiographically and delivery system 200 and/or stent-graft 100 mayinclude radiopaque markers as known in the art.

After stent-graft delivery system 200 is in the location where themobile external coupling 120 of the stent graft 100 is approximatelyaligned with the opening into the branch vessel, outer sleeve 210 isretracted proximally to a position adjacent to mobile external coupling120 to release mobile external coupling 120, as shown in FIG. 29 (alsoshown in FIG. 23). Mobile external coupling 120 provides a positiveoutward force due to coupling deployment device 132 that reduces thepossibility of the mobile external coupling 120 collapsing against orwithin body 107 after deployment. Delivery system 200 may then be movedand/or rotated to better align mobile external coupling 120 with thebranch artery, in this case, the brachiocephalic trunk 308. Further, dueto the configuration of mobile external coupling 120, even if it is notperfectly aligned with brachiocephalic trunk 308, the top of the mobileexternal coupling 120 may be moved to properly align its lumen openingwith the lumen of the brachiocephalic trunk 308 without having to movethe entire stent-graft 100. Force to adjust the position of the top ofthe mobile external coupling 120 can be created by pulling or pushing onthe end of second guide wire 222. Coupling deployment device 132, asexplained above, urges the distal end of mobile external coupling 120distally away from the main graft and into the lumen of the branchvessel.

Once mobile external coupling 120 is deployed and in position in thebrachiocephalic trunk 308, outer sleeve 210 may be further retracted asexplained above with respect to FIGS. 24, 25 and 24A, thereby deployingthe main body of the stent graft 100, as shown in FIGS. 24 and 25. Thestent capture fitting 282 is then retracted proximally to releaseproximal anchor stent 112 of stent 100 to fully release stent-graft 100,as shown in FIGS. 26 and 30. Once mobile external coupling 120 andstent-graft 100 are deployed, delivery system 200 may be removed. Secondguide wire 222 may remain in place in brachiocephalic trunk 308 or maybe replaced by another guide wire. A branch stent-graft delivery system404 is advanced over second guide wire 222 and into brachiocephalictrunk 308, as shown in FIG. 31. Branch stent-graft delivery systemincludes a tip 402 and a sleeve (not shown), and contains therein abranch stent-graft 400. Branch stent-graft delivery system 404 andbranch stent-graft 400 may be conventional. Branch stent-graft deliverysystem 404 is advanced into brachiocephalic trunk 308 such that aproximal portion 406 of branch stent-graft 400 remains inside of mobileexternal coupling 120. The sleeve constraining branch stent-graft 400 isthen retracted proximally, thereby releasing branch stent-graft 400 fromdelivery system 404. The delivery system 404 is then withdrawn, as shownin FIG. 32. Proximal portion 406 of branch stent-graft 400 is disposedwithin internal sealing cuff 134 (obscured in FIG. 32) when branchstent-graft 400 is expanded.

While various embodiments according to the present invention have beendescribed above, it should be understood that they have been presentedby way of illustration and example only, and not limitation. It will beapparent to persons skilled in the relevant art that various changes inform and detail can be made therein without departing from the spiritand scope of the invention. It will also be understood that each featureof each embodiment discussed herein, and of each reference cited herein,can be used in combination with the features of any other embodiment.All patents and publications discussed herein are incorporated byreference herein in their entirety.

1. An endovascular prosthesis having a radially collapsed configurationand a radially expanded configuration comprising: a tubular body havinga proximal end, a distal end, and a lumen disposed between the proximaland distal ends, the tubular body including a body graft material and aplurality of stents coupled to the body graft material; a mobileexternal coupling extending outwardly from the tubular body in theradially expanded configuration, wherein the mobile external coupling isgenerally frustoconically shaped and includes a base coupled to thetubular body, a top spaced from the tubular body, and a coupling lumendisposed between the base and the top, wherein the coupling lumen is inflow communication with the body lumen and wherein the mobile externalcoupling includes a coupling graft material; and a sealing cuff attachedto the top of the mobile external coupling in the radially collapsedconfiguration and the radially expanded configuration, the sealing cuffextending from the top of the mobile external coupling towards thetubular body within the coupling lumen in the radially expandedconfiguration, wherein the sealing cuff is formed from a graft materialand is generally cylindrically shaped.
 2. The prosthesis of claim 1,wherein the sealing cuff is a seamless woven tube of PET cloth.
 3. Theprosthesis of claim 1, wherein the sealing cuff is reinforced with acircumferential stent coupled thereto.
 4. The prosthesis of claim 3,wherein the circumferential stent is formed from a shape memory materialand formed into a sinusoidal configuration.
 5. The prosthesis of claim3, wherein the circumferential stent has a shape memory diameter that isat least 20% less than a diameter of the sealing cuff.
 6. A mainprosthesis and a branch vessel prosthesis assembly comprising: a mainprosthesis configured for placement in a main vessel, the mainprosthesis having a main prosthesis radially compressed configurationand a main prosthesis radially expanded configuration, the mainprosthesis including a tubular body and a mobile external coupling, thetubular body having a proximal end, a distal end, a body lumen disposedbetween the proximal and distal ends, and a body graft material, themobile external coupling extending outwardly from the tubular body inthe main prosthesis radially expanded configuration, and the mobileexternal coupling including a generally frustoconically shaped couplinggraft material and including a coupling lumen in flow communication withthe body lumen, wherein the mobile external coupling includes a basecoupled to the tubular body and a top spaced from the tubular body; abranch vessel prosthesis configured for placement in a branch vesselthat extends from the main vessel, the branch prosthesis having a branchprosthesis radially compressed configuration and a branch prosthesisradially expanded configuration, the branch vessel prosthesis includingan outer surface; and a cylindrical sealing cuff attached to the top ofthe mobile external coupling in the main prosthesis radially compressedconfiguration and the main prosthesis radially expanded configuration,the sealing cuff extending from the top of the mobile external couplingtowards the tubular body within the coupling lumen in the mainprosthesis radially expanded configuration, wherein the sealing cuffoverlaps a proximal portion of the branch vessel prosthesis such thatthe outer surface of the branch vessel prosthesis contacts an innersurface of the sealing cuff in the main prosthesis radially expandedconfiguration and the branch prosthesis radially expanded configuration.7. The prosthesis of claim 6, wherein a diameter of the sealing cuff inthe main prosthesis radially expanded configuration is smaller than adiameter of a portion of the branch vessel prosthesis that is notdisposed within the sealing cuff in the branch prosthesis radiallyexpanded configuration.
 8. The prosthesis of claim 7, wherein thediameter of the sealing cuff is up to 30% smaller than the diameter ofthe portion of the branch vessel prosthesis that is not disposed withinthe sealing cuff.
 9. The prosthesis of claim 6, wherein the sealing cuffis a seamless woven tube of PET cloth.
 10. The prosthesis of claim 6,wherein the sealing cuff is reinforced with a circumferential stentcoupled thereto.
 11. The prosthesis of claim 10, wherein thecircumferential stent is formed from a shape memory material and formedinto a sinusoidal configuration.
 12. The prosthesis of claim 10, whereinthe circumferential stent has a shape memory diameter that is at least20% less than a diameter of the sealing cuff.